<template>
  <!-- #ifdef H5 -->
  <th
    :rowspan="rowspan"
    :colspan="colspan"
    class="uni-table-th"
    :class="{ 'table--border': border }"
    :style="{ width: customWidth + 'px', 'text-align': align }"
  >
    <view class="uni-table-th-row">
      <view
        class="uni-table-th-content"
        :style="{ 'justify-content': contentAlign }"
        @click="sort"
      >
        <slot></slot>
        <view v-if="sortable" class="arrow-box">
          <text
            class="arrow up"
            :class="{ active: ascending }"
            @click.stop="ascendingFn"
          ></text>
          <text
            class="arrow down"
            :class="{ active: descending }"
            @click.stop="descendingFn"
          ></text>
        </view>
      </view>
      <dropdown
        v-if="filterType || filterData.length"
        :filterData="filterData"
        :filterType="filterType"
        @change="ondropdown"
      ></dropdown>
    </view>
  </th>
  <!-- #endif -->
  <!-- #ifndef H5 -->
  <view
    class="uni-table-th"
    :class="{ 'table--border': border }"
    :style="{ width: customWidth + 'px', 'text-align': align }"
    ><slot></slot
  ></view>
  <!-- #endif -->
</template>

<script>
// #ifdef H5
import dropdown from './filter-dropdown.vue';
// #endif
/**
 * Th 表头
 * @description 表格内的表头单元格组件
 * @tutorial https://ext.dcloud.net.cn/plugin?id=3270
 * @property {Number | String} 	width 	单元格宽度（支持纯数字、携带单位px或rpx）
 * @property {Boolean} 	sortable 					是否启用排序
 * @property {Number} 	align = [left|center|right]	单元格对齐方式
 * @value left   	单元格文字左侧对齐
 * @value center	单元格文字居中
 * @value right		单元格文字右侧对齐
 * @property {Array}	filterData 筛选数据
 * @property {String}	filterType	[search|select] 筛选类型
 * @value search	关键字搜素
 * @value select	条件选择
 * @event {Function} sort-change 排序触发事件
 */
export default {
  name: 'uniTh',
  options: {
    virtualHost: true
  },
  components: {
    // #ifdef H5
    dropdown
    // #endif
  },
  emits: ['sort-change', 'filter-change'],
  props: {
    width: {
      type: [String, Number],
      default: ''
    },
    align: {
      type: String,
      default: 'left'
    },
    rowspan: {
      type: [Number, String],
      default: 1
    },
    colspan: {
      type: [Number, String],
      default: 1
    },
    sortable: {
      type: Boolean,
      default: false
    },
    filterType: {
      type: String,
      default: ''
    },
    filterData: {
      type: Array,
      default() {
        return [];
      }
    }
  },
  data() {
    return {
      border: false,
      ascending: false,
      descending: false
    };
  },
  computed: {
    // 根据props中的width属性 自动匹配当前th的宽度(px)
    customWidth() {
      if (typeof this.width === 'number') {
        return this.width;
      } else if (typeof this.width === 'string') {
        let regexHaveUnitPx = new RegExp(/^[1-9][0-9]*px$/g);
        let regexHaveUnitRpx = new RegExp(/^[1-9][0-9]*rpx$/g);
        let regexHaveNotUnit = new RegExp(/^[1-9][0-9]*$/g);
        if (this.width.match(regexHaveUnitPx) !== null) {
          // 携带了 px
          return this.width.replace('px', '');
        } else if (this.width.match(regexHaveUnitRpx) !== null) {
          // 携带了 rpx
          let numberRpx = Number(this.width.replace('rpx', ''));
          let widthCoe = uni.getSystemInfoSync().screenWidth / 750;
          return Math.round(numberRpx * widthCoe);
        } else if (this.width.match(regexHaveNotUnit) !== null) {
          // 未携带 rpx或px 的纯数字 String
          return this.width;
        } else {
          // 不符合格式
          return '';
        }
      } else {
        return '';
      }
    },
    contentAlign() {
      let align = 'left';
      switch (this.align) {
        case 'left':
          align = 'flex-start';
          break;
        case 'center':
          align = 'center';
          break;
        case 'right':
          align = 'flex-end';
          break;
      }
      return align;
    }
  },
  created() {
    this.root = this.getTable('uniTable');
    this.rootTr = this.getTable('uniTr');
    this.rootTr.minWidthUpdate(this.customWidth ? this.customWidth : 140);
    this.border = this.root.border;
    this.root.thChildren.push(this);
  },
  methods: {
    sort() {
      if (!this.sortable) return;
      this.clearOther();
      if (!this.ascending && !this.descending) {
        this.ascending = true;
        this.$emit('sort-change', { order: 'ascending' });
        return;
      }
      if (this.ascending && !this.descending) {
        this.ascending = false;
        this.descending = true;
        this.$emit('sort-change', { order: 'descending' });
        return;
      }

      if (!this.ascending && this.descending) {
        this.ascending = false;
        this.descending = false;
        this.$emit('sort-change', { order: null });
      }
    },
    ascendingFn() {
      this.clearOther();
      this.ascending = !this.ascending;
      this.descending = false;
      this.$emit('sort-change', { order: this.ascending ? 'ascending' : null });
    },
    descendingFn() {
      this.clearOther();
      this.descending = !this.descending;
      this.ascending = false;
      this.$emit('sort-change', {
        order: this.descending ? 'descending' : null
      });
    },
    clearOther() {
      this.root.thChildren.map((item) => {
        if (item !== this) {
          item.ascending = false;
          item.descending = false;
        }
        return item;
      });
    },
    ondropdown(e) {
      this.$emit('filter-change', e);
    },
    /**
     * 获取父元素实例
     */
    getTable(name) {
      let parent = this.$parent;
      let parentName = parent.$options.name;
      while (parentName !== name) {
        parent = parent.$parent;
        if (!parent) return false;
        parentName = parent.$options.name;
      }
      return parent;
    }
  }
};
</script>

<style lang="scss">
$border-color: #ebeef5;

.uni-table-th {
  padding: 12px 10px;
  /* #ifndef APP-NVUE */
  display: table-cell;
  box-sizing: border-box;
  /* #endif */
  font-size: 14px;
  font-weight: 500;
  color: #333333;
  background: #d5f3ff;
  border-bottom: 1px $border-color solid;
}

.uni-table-th-row {
  /* #ifndef APP-NVUE */
  display: flex;
  /* #endif */
  flex-direction: row;
}

.table--border {
  border-right: 1px $border-color solid;
}
.uni-table-th-content {
  display: flex;
  align-items: center;
  flex: 1;
}
.arrow-box {
}
.arrow {
  display: block;
  position: relative;
  width: 10px;
  height: 8px;
  // border: 1px red solid;
  left: 5px;
  overflow: hidden;
  cursor: pointer;
}
.down {
  top: 3px;
  ::after {
    content: '';
    width: 8px;
    height: 8px;
    position: absolute;
    left: 2px;
    top: -5px;
    transform: rotate(45deg);
    background-color: #ccc;
  }
  &.active {
    ::after {
      background-color: #007aff;
    }
  }
}
.up {
  ::after {
    content: '';
    width: 8px;
    height: 8px;
    position: absolute;
    left: 2px;
    top: 5px;
    transform: rotate(45deg);
    background-color: #ccc;
  }
  &.active {
    ::after {
      background-color: #007aff;
    }
  }
}
</style>
